Charge Control; Audio - Nokia 1265 Description And Troubleshooting

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Charge Control

In active mode, charging is controlled by the PM's digital part. Charging voltage and
current monitoring are used to limit charging into a safe area. The PM has a
MaxPower protection limit at NPN transistor to cut-off charger.
Cut Off MaxPower = 1000mW
The PM limits the charging voltage to MaxVoltage.
MaxVoltage= 4.25V
The PM limits the total system current (the collector current of PNP transistor) by
limiting the maximum power of NPN transistor charge.

Audio

The audio control and processing is provided by the MSM which contains the audio
codec, the MCU and DSP blocks. These blocks handle and process the audio data
signals. The baseband supports 2 microphone inputs and three receiver (earpiece)/
speaker outputs.
MIC+ & MIC- inputs of 1265 schematic are used for the mobile terminal's internal
microphone. JACK_MIC+ & JACK_MIC- input are used for headsets.
Every microphone input can have either a differential or single-ended AC connection
to the QSC6010 circuit.
microphone (JACK_MIC) are both differential signals which come from different
sources and are connected to separate inputs at the QSC6010.
The MICBIAS output is used for MIC to provide 1 mA of current at 1.8 +/-0.11Volts
DC.
VDD_MSMP (2.8V) regulated voltage from PM is used for JACK_MIC (external
headset).
RECEIVER+ & RECEIVER- (of QSC6010 output pins) outputs are used for the
mobile terminal's internal receiver (earpiece).
The receiver and external louder speaker are both differential signals that come from
separate outputs at the QSC6010 are connected to different driver.
Issue 1 04/2007
The internal microphone (MIC+) and external headset
© 2007 Nokia Corporation
Baseband Description and Troubleshooting
Company Confidential
1265 (RH-103)
Page 17